Most batteries in that spec/style of laptop are in the ~5 hour range. The exception is in some of the newer models with detachable sleeves, or slices that can be added for more battery life. Those are all way out of your budget though. I know you said you had a preference for an AMD cpu, but might I suggest something like this to look at as well:http://www.newegg.com/Product/Product.aspx?Item=N82E16834230706
Here is one very close to your spec's as well to look at: http://www.newegg.com/Product/Product.aspx?Item=N82E16834312641
Edit's: sorry linked the wrong one originally.